Condenser storage equipment



July 23, 1940. E. P. G. WRIGHT CONDENSER STORAGE EQUIPMENT Filed Nov. 19; 1938 Fla.

//v VENTOR By E P; G. WR/GH T ATTORNEY Patented July23, 1940 2,208,655 connsnsea sromcn EQUIPMENT Esmond Philip Goodwin Wright, London, England, assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application November 19, 1938, Serial No. 241,423

In Great Britain January 4, 1938 10 Claims. (01. 179-16.)

UNITED STATES PATENT OFFICE This invention relates to condenser charging circuits and more particularly to equipment for successively and periodically testing a plurality of condensers to determine if they have been charged and to boost the charges on such condensers as are found to have been' charged to an eflective value.

It is well-known practice in the electrical art to charge a condenser and to thereafter discharge the condenser through the winding of a relay or other electromagnetic device for causing the operation of such 'relay or device.

If the interval between the charging and dis charging of the condenser is long, leakage irom the condenser due to the resistance of the condenser and connected wiring, may permit an appreciable amount of the charge to leak away and the discharge of the condenser will then be insumcientto operate the connected relay or device.

As an example of the use of condensers for operating relays associated therewith by the discharge of such condensers, reference may be had to the application of M. S. Snell and E. P.

Wright, Serial No. 185,858 filed January 30, 1938,

or to the corresponding British Patent No. 476,088 of 193? which disclose a sender for use in a telephone system in which groups of condensers are employed for storing the digits of the di= at) rectory number of a wanted subscriber's line, the condensers of each group being selectively charged, either positively or negatively to store difierent digits. in the setting up of a connection to the line the digits of whose number have been thus stored,' the group oi condensers are successively associated with relays which are controlled by the discharge of the condensers to, in turn ,-control impulse sending mechanism. Such condenser groups may also be used for num- 49 her storage-Jo! automatic ticketing systems in automatic telephone exchange systems, for. in-

stance, under circumstances in which the storage must endure throughout a telephone conversation, whatever its duration.

It is the object of the present invention to pro-- These objects are attained in accordance with the present invention by the provision of a testing and recharging equipment which successively and periodically testsa plurality ofcondensers to determine which or them have been placed 5 in a charged condition and which applies to such 01 the condensers as are found to be in a charged condition, a charging potential of the same polarity as the detected charge to raise the charge on such condensers to a required potential. 10

The invention will be more clearly understood from the following detailed description of two embodiments thereof taken in connection withthe accompanying drawing in which:

Fig. 1 shows a testing and recharging equipl5 ment for a plurality of condensers, the charges of which are always of the same polarity; and

Fig. 2 shows a testing and recharging equipment for a plurality of condensers, the charges of which may be either of positive or negative polarity.

Referring first to Fig. 1, two of a plurality of condensers M and M and a charging circuit for one of the condensers M are disclosed. The charging circuit for condenser l e; tends from the positive pole or" battery it whose negative pole is grounded, through a suitable resistance over the contact of a charging relay A which may be operated in any suitable manner, through the condenser M to ground. So long as the relay A remains operated a full charge will be maintained on the condenser IVE. After the relay A releases, condenser M will remain charged although it will he assumed that some of the charge will slowly leal: away. Other condensers M may he similarly charged.

Associated with the condensers is a switch R having a wiper rm which may be advanced step-by-step over the terminals of an associated banlr by the stepping magnet RM under the control of stepping relay D which, in turn, is periodically operated and released by the interrupter IL. The bani: terminals are respectively connected to the ungrounded terminals oi the condensers. I

When in the operation of the switch R the wiper rm engages the first terminal of the bank to which the condenser M is connected, if this condenser hasbeen charged by the operation and subsequent release of relay A, a discharge circuit for thiscondenser will be established from ground through the condenser over wiper rm, the upper back contact of relay D through the winding of relay 0 to ground. Relay C operates in this discharge circuit and locks in a circuit extending from ground through its winding over the upper back contact of relay D over its own front contact through resistance W to the positive terminal of the battery '13, the negative terminal of which isgrounded.

During the time that relay. C remains operated, or until relay D subsequently operates,-a recharging circuit for condenser M is established from the positive terminal of battery E through resistance W over the contact of relay C, wiper rm, through condenser M to ground and the charge on condenser M is restored to a value which will be adequate to operate any device to be controlled thereby.

Upon the next closure of the interrupter contact IL, relay D operates releasing relay and stepping magnet RM and the magnet RM upon releasing advances wiper rm one step. Upon the next opening of the interrupter contact IL relay D releases again operating magnet RM preparatory to advancing the wiper 1112. another step and connecting test relay C over the wiper rm to the next condenser M. This condenser is now tested and recharged if required. In this manner, as the switch R is advanced step bystep at intervals predetermined by the interrupter IL, successive condensers are tested and recharged. I

Should any condenser be tested and found to have not been initially charged to indicate a selective controlconditiomrelay C will not be operated and consequently while the switch wiper is standing on the bank terminal to which. such condenser is connected, no circuit will be established for applying recharging current from battery E to the condenser.

Referring now to Fig. 2, a testing and recharging circuit is shown for use with a plurality of condensers which may have been initially charged either positively or, negatively. Two such condensers M and M and the charging circuit of condenser M are disclosed. The charging circuit of. condenser M may extend from ground through the condenser overcontacts of relay A through a suitable resistance to'the positive terminal of battery E, the negative terminal of whichis grounded, or over the contacts of relay B through a suitable resistance to the negative terminal of battery E the positive terminal of which is grounded dependent on whether relay A or relay B is operated.

Other condensers such as W may be similarly charged.

Associated with the condensers is a switch R having a wiper rm which may be advanced step by step over the terminals of an associated bank by the stepping magnet RM under the control of the stepping relay SA. Relays SA and SB are alternately operated and released by the interrupters NFL and FNL. The interrupters may be driven from a common shaft at such a speed that the contacts of interrupter FNL are closed for 750 milliseconds while the contacts of in-' terrupter NFL are open for the-same period and the contacts of interrupter NFL are closed for 750 milliseconds while the contacts of interrupter FNL are open for the same period. The bank terminals of switch R are respectively connected to the ungrounded terminals of the condensers.

When in the operation of the switch R the wiper rm engages the first terminal of the bank to which the condenser M is connected, if that condenser has been charged positively by the operation and subsequent release of relay A a I Thus the condenser" may be either positively or negatively charged. I

discharge circuit for this condenser will be established from ground through the condenser over wiper rm, upper contacts of relay SB when that relay is operated by the closure of the interrupter contacts FNL through the rectifier MRB and the winding of test relay T to ground. Relay T will thereuponv operate and lock in a circuit extending through its winding and rectifier MRB, the lower contacts of relay T and the lower contacts of relay 'SB through resistance W to the positive terminal of battery E, the negative terminal of which is grounded.

During the interval that relay SB remains operated by the closure of interrupter contact FNL a recharging circuit for condenser M is established from the positive terminal of battery E','

through resistance W, over the lower contacts of relays SB and T, the upper contacts of relay SB, wiper rm' through condenser M to ground and the charge on condenser M will be restored to its initial positive value.

Had condenser M been initially charged negatively, the discharge path-therefor just traced through the rectifier MRB would not have been efiective, and consequently, test relay T would not have been operated during the interval that relay SB was operated. However, upon the re-' lease of relay SB by the opening of the interrupter contacts FNL and the operation of relay SA by theclosing of interrupter contacts NFL an effective discharge circuit is established for condenser M from ground through the condenser over wiper rm, the inner upper contact of relay SA, through rectifier MRA and the winding of test relay T to ground. Relay T will thereupon operate and lock in a circuit extending through its winding and rectifier MRA, the upper contacts of relay T, the upper contacts of relay SA, through resistance W to the negative terminal of battery E the positive terminal of contacts of relays SA and T, the inner upper contacts of relay SA and wiper rm, through condenser M to ground. and the charge on condenser M will be restored to its initial negative value.

Relay SA upon operating also closes the circuit for stepping magnet RM preparatory to advancing the wiper rm another step. As soon as the interrupter NFL opens its contacts and relay SA consequently releases, the circuit of magnet RM is opened and the switch wiper rm is advancedinto a position to test the charged condition of another condenser. such as M'-'.

The test could in each case be made by a thermionic or a gaseous discharge tube responsive to the potential on the condenser.

In the use of the proposed testing and recharging circuit it would probably be desirable to test and boost the charges on condensers at about half-hour intervals.

What is claimed is:

1. In a signaling system in which a condenser is charged to indicate a desired control condition, means for testing said condenser to detect the charged condition thereof, and means responsive to said testing means for boosting the 'charge on said condenser if a charge is found thereon.

2. In a signaling system in which a plurality of 7 condensers are selectively charged to indicate desired control conditions, means forv successively testing said condensers to detectthe charged condition thereof, and means responsive to said test- 5 ing means for boosting the charge on any of said condensers if a charge is found thereon.

3; In a signaling system in which a plurality of condensers are selectively charged to indicate desired control conditions, means for successively testing said condensers periodically at desired time intervals todetect the charge condition thereof, and means responsive to said testing meansfor boosting the charge on any of said condensers if a charge is found thereon. l5 4. In a signaling system in which a condenser is charged either positively or negatively to indicate desired control conditions, means for testing said condenser to detect the charged condition thereof, and means responsive to said testmg means for boosting the charge on said condenser to a higher positive or negative value in accordance with the initial charge if a charge is found thereon.

5. In a signaling system in which a plurality of 26, condensers are selectively charged either positively or negatively to indicate desired control conditions, means for successively testing said condensers to detect the charged condition thereof, and means responsive to said testing means for J 80 boosting the charge on any or said condensers to a higher positive or negative value in accordance with the initial charge if a charge is found thereon.

6. In a signaling system in which a condenser is charged to indicate a desired control condition,

a' test relay, means for establishing a discharge circuit from said condenser to said relay whereby said relay is operated if said condenser is in a charged condition, a source of current and a re- 40 charging circuit for said condenser from said source of current controlled by said relay.

7. In a signaling system in which a plurality of condensers are selectively charged to indicate desired control conditions, a test relay, a switching 45 means for successively and periodically establishing a discharge circuit from said condensers to said relay whereby said relay is operated if any one of said condensers is in a charged condition, a source of current and a recharging circuit from 50 said source controlled by said relay for recharg- 8. In a signaling system in which a plurality of condensers are selectively charged to indicate desired control conditions, a test relay, a switch, means for advancing said switch step by step to successively and periodically establish discharge circuits from said condensers to said relay whereby said relay is operated ifany one of said condensers is in a charged condition, a source of current and a recharging circuit from said source controlled by said relay for recharging any one of 10 said condensers found to be in a charged condition.

9. In a signaling system in which a plurality of condensers are selectively charged either positively or negatively to indicate desired control conditions, a test relay, an operating circuit for said relay having two branches, said branches being provided with oppositely poled polarity discriminating devices, means for valternately rendering said branches efiective, a switching means 2 for periodically extending said operating circuit to successive ones of said condensers whereby said relay is operable if anyone of said condensers is found to be in a positively or negatively charged condition, sources of current of opposite polarities and recharging circuits from said'sources controlled by said test relay and said first means for recharging any one of said condensers found to be in a charged condition to a higher positive or negative value in accordance with' its initial charged condition.v

10. In a signaling system in which a plurality of condensers are selectively charged either positively or negatively toindicatedesired control conditions,

a test relay,an operating circuit for said relay havmg two branches, said branches being provided with oppositely poled polarity discriminating devices, two relays alternately and periodically operable for rendering said branches eflectivaaswitch. 1

means controlled by one of said latter relays for advanciiigis'aid switch step by step for extending said operating circuit to successive ones of said condensers whereby said test relay is operable if any one of said condensers is found to be in a positively or negatively charged condition, sources of current of opposite polarity and r circuits from said sources controlledby said test relay and said latter relays for recharging any,

,one of said condensers found to be in a charged condition to a higher positive or negative value in accordance with its initial charged condition. ISMOND PHILIP GOODWIN WRIGHT. 

